HOW TO BUILD MULTI-CONTAINER DOCKER COMPOSE STACKS

Docker Compose simplifies local development by defining and running multi-container Docker applications through a declarative YAML configuration file.

1. RECOMMENDED 3-TIER ARCHITECTURE

• Application Layer: Node.js, Python FastAPI, or Go container with hot-reloading volume mounts.
• Database & Cache Layer: PostgreSQL 16 on persistent named volumes + Redis 7 for caching and pub/sub.
• Ingress Layer: Nginx reverse proxy routing port 80/443 traffic to your internal application containers.

2. SAMPLE DOCKER-COMPOSE.YML

version: '3.8'

services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - DATABASE_URL=postgres://user:pass@db:5432/app_db
    depends_on:
      - db
      - redis

  db:
    image: postgres:16-alpine
    environment:
      POSTGRES_USER: user
      POSTGRES_PASSWORD: pass
      POSTGRES_DB: app_db
    volumes:
      - pgdata:/var/lib/postgresql/data

  redis:
    image: redis:7-alpine

volumes:
  pgdata: